DESMIN MYOPATHY WITH CARDIOMYOPATHY

We report a case of abnormal desmin accumulation within the muscle of a 30-year-old female with a 2-year history of cardiomyopathy and axial muscle weakness. Serum creatine kinase was normal. A quadriceps muscl e biopsy revealed pink hyaline inclusions, which stained for acid phos phatase and with PAS and were present in both fibre types. Electron mi croscopy showed these inclusions to consist of aggregates of irregular ly arranged 6- to 15-nm-diameter filaments enmeshed within a central c ore of dense granule-amorphous material. In other areas, the granulo-a morphous material lay as irregular patches within the sarcoplasm, main ly at the level of the ''Z'' band causing disruption of the sarcomere. Immunoelectron microscopy using colloidal gold showed that the dense amorphous material reacted strongly with desmin antisera and could, th erefore, represent a defective or phosphorylated form of the protein.